1. Field of Invention
This invention generally relates to cradle boat lifts, specifically to providing an add-on structure to cradle boat lifts that eliminates the swinging motion of cradle boat lifts during high wind conditions.
2. Discussion of Prior Art
A boat is typically lifted from water by positioning a cradle below the surface of the water and positioning a floating boat above the cradle. Cables, engaged by pulleys, lift the cradled boat out of the water. A typical cradle is square or rectangular in configuration, and includes a pair of longitudinally disposed, transversely spaced apart, frame members that are interconnected to one another at their respective opposite ends by transversely disposed braces. Cable-engaging pulleys are mounted at opposite ends of each frame member or cradle beam. Overhead motorized winches, mounted on pilings or other suitable support surfaces, are used to raise and lower the cradle.
A conventional cradle boat lift includes four (may also be 6 or 8) pilings that are driven into a sea bed adjacent a pier, wharf, or dock in a generally square or rectangular array. A first pair of pilings is positioned close to the dock. The second pair is positioned away therefrom by a distance substantially equal to the width of a boat and a reasonable amount of clearance. A first winch surmounts the first or inboard set of pilings and a second winch surmounts the second or outboard set.
A boat is positioned between the inboard and outboard pilings, above a pair of cradle beams, such that its longitudinal axis is substantially parallel to a first centerline drawn through the first set of pilings and therefore substantially parallel to a second centerline drawn through the second set of pilings. Four upstanding guide poles are mounted to the cradle beams to guide the boat to its proper position.
Cradle boat lift owners enjoy the convenience of simple, waterway yet, out of water, storage for their boats. Both the boat and the lift parts are stored out of water, protecting them from excessive wave action, corrosive saltwater damage and crustacean growth.
Davits and elevator lifts are alternative designs of residential boat lift structures. One or two davits can be used to lift the boat and swing it onto land. This method requires a landing for the boat, for protection from grass and mud, and uses up back yard space. Davits can be tricky to use. Clearly, a boat swinging on a lifted cable is potentially dangerous and vulnerable. Elevator lifts employ a cradle attached to angled beams along the sea wall. The lift motor raises the cradled boat along the beams and up, out of the water. Unfortunately, the elevator lift employs metal beams that remain in the water, exposed to water and especially salt water's corrosive properties. Davits and elevator lifts provide one or two points of strength, compared to the cradle boat lift's usual minimum of four points of strength.
Owners of cradle boat lifts enjoy the benefits of simple, safe, waterway access and storage for their boats. Vessels are protected from floating debris and free from concerns over excess wave action. The boat owner's maintenance costs are decreased due to the elimination of corrosive saltwater damage and crustacean growth on the hull and boat lift elements experienced by boats stored floating or on elevator lifts in the waterways. Because of these abundant benefits, recreational boaters who are fortunate enough to live on or own property along navigable water are having more and more multi-post cradle boat lifts installed each year.
All is well until tropical storm or hurricane force winds are experienced. Unfortunately, the cables that so conveniently allow the boat to be raised and lowered from the water, can also allow the cradle to swing dramatically when exposed to high wind conditions. The boat and lift repeatedly swing and slam as the storm rages. Damage can occur to the boat lift, dock, pilings, guide poles, and both sides of the boat.
When hurricane force winds are expected, cradle boat lift owners are recommended to remove their boat from the lift and put it on land in preparation for hurricane force winds. While prudent, this plan is not practical for many boaters. Boaters are reluctant to go to the expense and effort of having a trailer and trailer vehicle available for hauling their boat from the water and insuring a space on land to secure the boat. In recent years, multiple hurricanes have been anticipated each year. Each hurricane's predicted cone of possibility has spanned hundreds of miles in the Atlantic and Gulf state regions where many homesteads on navigable water exist. The process of repeatedly hauling a boat to dry ground in preparation for hurricanes that are predicted, but may not even materialize, is cumbersome, expensive, time-consuming and downright frustrating.
Mooring boats in the water is the second recommendation for storm preparation. However, special knowledge is needed to successfully use lines to allow for adequate scope for storm surge and wave action, while limiting the boat's scope from hitting seawalls, trees, neighboring boats or other dangers. The mooring option also exposes the boat to floating debris that can be expected to randomly occur in hurricane conditions.
If rejecting the previous hurricane preparation options, boaters are recommended to raise their boat lift to a high level, storm level, and strap the boat to the lift. Raising the boat to storm level serves two purposes: (1) to shorten the length of the cable wires and therefore the potential swing of the boat lift and (2) to raise the boat as far above sea level as possible to minimize the effects of storm surges and oversized floating debris. Unfortunately, even at storm level, hurricane force winds can cause the cradle to swing and slam the boat, exposing the boat owner to potentially expensive damage to the boat lift, dock, pilings, guide poles, and both sides of the boat.
To overcome this swinging motion, some cradle boat lift owners have used lines to tie the boat lift to the pilings in various ways. This process is time and line consuming. It often requires 2 persons to execute or one person who is willing to repeatedly climb off and on a lifted boat to attach the lines to the boat, lift and pilings. Paradoxically, lines are manufactured to stretch. This property, while very useful in everyday boating, makes it difficult to achieve a tight connection. Once the storm hits, hurricane winds are likely to stretch the lines and allow potentially damaging movement to still occur before the wind event is over.
All of the above methods of storm preparation, while inconvenient, are obvious steps for the boater to consider. Taking the next step, adding-on strength to the lift, is not obvious, nor simple to achieve and is therefore a new and innovative solution.